FOUNDATION FOR CROSS-CONNECTION CONTROL
AND HYDRAULIC RESEARCH
Volume 141 Number 1 I April1996
Why Does the Relief Valve
Opening Point Change?
hen a backflow prevention assembly tester tests
a reduced pressure
principle assembly, the tester
expects to fmd certain results.
The relief valve opening point
should be at least 2.0 psid (pounds
per square inch differential) and
the first check reading should be
at least 3.0 psid above the reading
o btained on the relief valve. This
W
if the tester activates the reliif
valve and then determines the
reliif valve opening paint, the
reading is likely to be higher
than the tester determined
the reliif valve opening point
without first exercising the
reliif valve.
if
still leaves plenty of room for
various readings. One question,
that many testers have is: Why do
the readings vary on the same
assembly each time it is tested?
The opening point of the
relief valve is determined, in part,
by the relief valve spring. The
rings are designed to operate
within specific tolerances. They
may vary slightly after they are
fully compressed. After some initial
use, the spring will "set" or settle in
atafairlyconsistentpoint. However, one may still find that the relief
valve opening point changes.
The spring is not the only
factor which determines the relief
valve opening point. In fact, there
may be several factors involved
depending upon the design of the
relief valve. One of the primary
factors will be the sliding surfaces
within the relief valve. When the
relief valve opens some of the
surfaces slide against other surfaces, such as guide stems. In
some cases the sliding surfaces
operate as a piston in a cylinder.
The condition of the surfaces may
change depending upon the local
water conditions and how much
exercise the relief valve gets.
If the relief valve is being
exercised on a regular basis the
sliding surfaces will glide freely
without any hindrances. However, if the assembly has been
sitting for a while without any
relief valve activity, some small
deposits from the water may build
up upon the sliding surfaces
requiring more force to move
them, thus a lower relief valve
opening point. If this is the case,
Continued on page 3
E. Kent
Springer
Protector of
Public Drinking Water
E. KENT SPRINGER, Director
Emeritus of the Foundation for
Cross-Connection Control and
Hydraulic Research at the University of Southern California and
Professor Emeritus of Mechanical
Engineering at the University of
Southern California passed away
Monday the fourth of December
1995.
For nearly twenty years,
Prof. Springer headed the Foundation, he was responsible for
Continued on page 3
2
0
The Foundation Staff would like to welcome the following new Members to the Membership
Program. Remember all Members are welcome to contact the Foundation Office with any questions
regarding cross-connection control. Also, Members are granted discounts on Courses, Manuals and
Training Tools. We trust your Foundation Membership will be a great benefit to you in your crossconnection control efforts.
A. C. Austin's Plumbing
City of Hurst
ABC Plumbing & Heating
John S. Kern, P.E., P.C.
ABC Plumbing, Heating &
City of Ketchikan
Air Conditioning
Alexander Plumbing, Inc.
C. "Herb" Berger
California Commercial
Plumbing
California State Univ.,
Fresno
Cisco Fire Sprinklers
Cross Connection
Consultants, NV
Denny's Plumbing
City of Exeter
L. Nothhaft & Son, Inc.
Litton Guidance
& Control Systems
City of Lompoc
Louisiana Water Service Inc.
Pete's Plumbing
Pinellas County
Utilities Engineering
RCI Sales & Marketing, Inc.
City of Richmond, TX
Sarasota County
Utilities Dept.
City of Firebaugh
SC Johnson Professional
Foodmaker, Inc.
Westinghouse Electric
Town of Gilbert
City of Holtville
Cross Talk is published by
the University of Southern
California's Foundation for
Cross-Connection Control
and Hydraulic Research for
its Members. Additional
Copies are available to the
Members upon request.
(213) 740-2032 Copyright
1996 © University of Southern California.
All rights reserved.
Corporation
City of Woodlake
The Foundation for Cross-Connection
Control and Hydraulic Research
University of Southern California
KAP-200 University Park MC-2531
Los Angeles, CA 90089-2531
Phone: (213) 740-2032
FAX: (213) 740-8399
E-Mail: fccchr@usc.edu
WWW Homepage:
http://www.usc.edu/dept/fccchr/
0
3
o~:~!~~~lve Opening Point
Professor Springer
Continued from page 1
the relief valve may have a higher
reading if tested again immediately following the initial test.
This is why it is so important for
the tester not to activate the relief
valve before determining the relief
valve opening point. If the tester
activates the relief valve and then
determines the relief valve opening point, the reading is likely to
be higher than if the tester determined the relief valve opening
point without first exercising the
relief valve. A stiff diaphragm
may also have a similar effect.
Another cause for various
readings for the relief valve
opening point may be differing
line pressures. The relief valve of
each reduced pressure principle
ackflow preventer is required to
pen at a pressure differential
across the frrst check valve of 2.0
psi or greater at various line
pressures from 20 psi up to and
including the maximum working
d
0
water pressure of the assembly.
While at each pressure, the opening point must be at least 2.0 psid,
readings can vary depending upon
the line pressure. So, a difference
in line pressure alone may be
cause for differing readings for the
relief valve opening point.
In summary, It is important
for the tester to remember that
exercising the relief valve before
determining the relief valve
opening point can lead to artificially high readings on the relief
valve. Readings obtained for the
relief valve opening point may
vary. This may be due to frequency of the operation of the
relief valve, or simply varying line
pressures. This does not mean
there is any thing wrong with the
relief valve as long as it is operating within the design parameters,
that is opening at 2.0 psid or
higher.
Under certain water conditions mineral deposits may form on the
sliding surfaces of the relief valve. This may cause the relief valve
reading to vary, depending upon the amount of deposits
leading the Foundation into the
position it has as a world's authority on cross-connection control.
Springer was responsible for
establishing the Foundation •sField
Evaluation Program for the evaluation ofbackflow prevention assemblies-the only full-time program of
its kind in the world.
In 1967 Professor Springer,
worked closely with the Southern
California Water Utilities Association and Mr. Walter 0. Weight
to develop the Foundation's
Membership Program in order to
assure funding of the Foundation's
important work. Originally the
Southern California Water Utilities Association (SCWUA) organized the Foundation's Membership program by asking its Members to donate funds for the
Foundation's work. The SCWUA
collected the Foundation's Membership fees from its Members
which chose to participate in the
Foundation's Membership Program, transferring funds to the
Foundation when they were
collected.
Prof. Springer also developed
the Foundation's five-day Course
for the Training of Backjlow
Prevention Assembly Testers and
offered the first course in 1970.
Professor E. Kent Springer taught
the first Tester Training Course
with the assistance of Mr. Ernest
J. Havlina of the Los Angeles
Department of Water and Power.
The Fourth Edition of the Manual
of Cross-Connection Control was
used for this course which had
Continued on page 4
4
Professor Springer
Continued from page 1
nineteen students from California,
Idaho, Missouri, Oregon, Pennsylvania, and Washington. From the
flrst year this course was introduced, the Foundation offered the
course in various locations to help
train personnel throughout the
country. Originally
Professor Springer
handled all of the away
courses with the help of
some local personnel.
He joined the USC School
of Engineering as an associate
professor of mechanical engineering in 1946. He became a full
professor there in 1951. He
became interested in the work of
the Foundation in the mid-50's
Professor Springer
was truly instrumental in
the development of the
fleld of cross-connection
control. His efforts not
only brought the Foundation to the forefront of the
field, but have also resulted in safer drinking
water throughout North
America and other parts of
the world.
He was also
a member of several
organizations that
promote safe drinking
water and engineering
education. They
include the American
Water Works Association, the American
Society for Engineering Education, the
Southern California
Water Utilities Association and the City of
Pasadena Blue Ribbon
Committee reviewing
the Pasadena Department of Water and
Power.
Q
Springer was born
Sept. 17, 1912, in
Bellingham, Wash. After
earning his B.S. degree in
mechanical engineering
from the USC School of
Engineering in 1936, he
worked as a plant engineer at the Fluid Packed
Pump Co. in Los Nietos,
Calif., and, later, as a
mechanical engineer for
the Pacific Railway
Equipment Co. in Los
Angeles.
Springer joined the faculty
of the University of Wisconsin,
Madison, in 1941. While teaching
at the University as an instructor
and later as an assistant professor,
he earned a master's degree in
mechanical engineering in 1945
from the University of Wisconsin.
0
Springer was a fellow of
the American Society of Mechanical Engineers and held several
distinguished positions, including
vice president of Region IX, in
that organization. For a number
of years, he was the faculty adviser to the USC
student section of the
ASME. In 1981, the
Los Angeles section of
the ASME awarded its
Centennial Medal to
Springer for his years
of dedicated service.
and co-authored the document
USCEC 48-101, published in
1959, which became the basis for
the 1st Edition of the Manual of
Cross-Connection Control. He
served as director of the Foundation for Cross-Connection Control
and Hydraulic Research from
1965 until his retirement in 1984.
Springer is
survived by his wife,
Frances, and son
Bruce, a mechanical
engineer. A memorial
scholarship fund has been established at the Foundation. Contributions may be sent to: CrossConnection Control Pioneer's
Scholarship Fund, USC Foundation for Cross-Connection ContrcQ
and Hydraulic Research,
Kaprielian Hall 200, Los Angeles,
CA 90089-2531.
5
Tenth Edition of the Manual
0 ../n a couple of years
you'd like to
see specific
additional
material,
please let the
Manual
Review
Committee
know.
0
N
though the Ninth Edition
f the Manual of Crossonnection Control has
only been available for just over
two years, it is time to begin work
on the Tenth Edition. The Ninth
Edition of the Manual was the
most comprehensive revision to
date. At this point there is no way
to tell what the Tenth Edition will
include, but the Manual Review
Committee will convene later this
year to begin preliminary discussions.
The Manual Review Committee is comprised of Water
Agency personnel, Health Agency
personnel, private testers and
Foundation Engineering Staff
~embers. The Committee accepts
\.._):omments and suggestions from
all Foundation Members. If
you've noticed things you feel are
missing from the Manual, or
The
review process for the
Ninth Edition
of the Manual
took over 2 1h
years. So, it
could be quite
some time
before the
Tenth Edition
is actually at
the point of
publication.
However, the Members are encouraged to keep in mind the fact
that the Manual will be under
revision. Whenever, you come
across something you would like
to have added to the Manual or
changed, let the Manual Review
Committee know. These suggestions wAill be discussed in the
committee and possibly added to
the Tenth Edition of the Manual.
You can contact the Manual
Review Committee care of the
Foundation Office.
Manual Review Committee
Foundation for Cross-Connection
Control and Hydraulic Research
University of Southern California
Kaprielian Hall 200
Los Angeles, CA 90089-2531
E-Mail: fccchr@usc.edu
T-Shirts and Hats
The Foundation has made available a small supply
ofT-shirts
-~-and baseball caps.
TheTshirts are
available
in Extra
Large.
The
baseball
caps are
embroidered in two colors. There
---~ is a limited supply,
but Members who
would
like to
receive
one or
the other
may
purchase
them
from the Foundation Office. The
T-shirts are $10.00 and the caps
are $15.00. We will pay the
shipping charges.
The Foundation is preparing to accept Visa, Mastercard,
and Discover. This has been in
the works for quite some time, but
finally these cards will be accepted by the Foundation Office.
This will make taking orders by
FAX, phone and even e-mail a
possibility.
The Foundation is
working
with other
departments at the
University to get the
system implemented.
The cards
should be
accepted in
early April.
6
USC Loses the Logo
T
he University of Southern
California has introduced a
new logo to be used
throughout the University community. After almost thirty years of
the same logo, the University has
gone to a new look. The new logo
will be phased in over the next
several months and will affect
every department of the
University.
This also
means the
Foundation's
logo will be
retired in
favor of the
new University Logo.
The
University's
Board of
Trustees felt
the
University's
image had
suffered as a
result of
disjointed use of the logo by
various University departments.
As an example, many may not
have made the association with
USC as being the University of
Southern California which is
home of Prof. George Olah, who
earned the Nobel Prize in Chemistry, the Trojan Football Team and
the Foundation for Cross-Connection Control and Hydraulic Research. The change of logo will
bring a uniformity to all entities of
the University, thus tying together
the various facets of the University of Southern California.
Although the old logo
worked extremely well for the
Foundation, many departments on
campus had adapted the logo to
the point that the use of the logo
was inconsistent across the campus. This is the main reason the
University's Board of Trustees has
decided to change the University
logo to a single image to be used
throughout the University community.
ITY
ERN
The
Foundation's
logo will disappear over the next
few months. You
will notice, the
Foundation's
letterhead, FAX
cover sheets,
business cards,
newsletters, etc.
all changing to
the new logo
format. Nothing
at the Foundation
has changed, the
logo is simply
changing to come
into compliance
with the new
University
policies.
You will notice the change
ftrst if you receive a fax from the
Foundation. The new fax cover
sheets are already in use. Within a
few weeks letterhead and business
cards will change, and fmally by
the end of the year, Cross Talk
and the List ofApproved Backflow
Prevention Assemblies will be
printed using the new University
Logo.
The change has already taken
place on the Foundation's Web
site. Those Members with Internet access can see the change by
accessing the Foundation's Web
pages.
Tester Training
Courses
O
ver the last several years
the Foundation has raised
the level of proficiency
required of those attending the
Tester Training Courses. More
time is devoted to the review of
troubleshooting, ensuring that the
attendees will be capable of
handling most of the real world
conditions which they may encounter in the fteld.
O
A Tester Training Course is
being offered in Hilo, Hawaii.
This course will be offered during
the week of 17-21 June 1996 and
is being held in conjunction with
the Hawaii Department of Water
Supply.
The Foundation is also
offering a course in Las Vegas,
Nevada during the week of 23-27
September 1996. This course is
being held in conjunction with the
Las Vegas Valley Water District.
0
Both of these courses are
Five Day courses teaching the
attendees how to test the double
check valve assembly, the reduced
pressure principle assembly and
the pressure vacuum breaker
assembly. The attendees will
spend much of their time in the
wet lab area testing and troubleshooting the actual backflow
preventers under guided instruction.
For more information and an
application for either of these
courses, or information on hosting
a course in your area, please
contact the Foundation Office.
O
Phone: (213) 740-2032
FAX: (213) 740-8399
E-Mail: fccchr@usc.edu
7
oVisit the Foundation's Web Site
T
he Foundation
has been using the
World Wide Web
to provide information
to its Members and
others requesting information on backflow
prevention and crossconnection control. It is
also being used as a
means of asking questions of the
Foundation's Engineering Staff. A reply is
usually made within one
day and in many cases
within minutes.
d
usc
UNIVERSITY
OF SOUTHERN
CAUFORNIA
On the Web you
will be able to fmd
much information.
echnical information
vailable includes: a
general introduction to crossconnection control, past issues of
Cross Talk, detailed information
about the Foundation's Approval
Program for backflow prevention
assemblies, special notices and the
List ofApproved Backflow Prevention Assemblies.
Members with Web
access don't have to wait
until the next printed
edition of the List is
released to find the latest
Approval information
0
The List published on the
eb is updated as new Approvals
are granted and other changes are
made. This means Members with
Web access don't have to wait
until the next printed edition of
the List is released to fmd the
latest Approval information.
Special notices are also listed on
the Web site. As soon as a special
notice is issued Members who
have sent the Foundation their EMail addresses are notified by
email that a new Notice has been
issued. Additionally, Members
are notified when there is a change
in the List ofApproved Backflow
Prevention Assemblies. This way
Members don't have to keep
checking to see if there are any
changes, they are notified automatically.
If you have not given the
Foundation your E-mail address,
please do so. This will allow us to
notify you when Special Notices
are issued and when the List
changes.
need special instructions and a
password to access the List. You
can E-Mail the Foundation with
your name, the name of the Member company or organization, and
the name of the Member contact
of the company or organization
(that's the name on the mailing
address of this issue of Cross
Talk). Once you submit this
information along with your EMail address, we will E-Mail
instructions to you and a password
for accessing the List. Foundation
Membership is based on company
or organization Membership, so
any employees of the company or
organization may be placed on the
Foundation's E-Mail mailing list.
Foundation Web Site:
http://www .usc.edufdept/fccchr/
Foundation E-Mail:
fccchr@usc.edu
Access to the List is restricted to Members so you will
10-12 April1996
CA/NV A WWA Spring Conference
Redding, CA
Tester Training Courses
24 April1996
Western States Symposium Association/American
Backflow Prevention Association Seminar
Fresno, CA
13-17 May 1996
Los Angeles, CA
15-19July 1996
Los Angeles, CA
17-21 June !996
Hilo, HI
5-9 August 1996
Incline Village, NV
23-27 September 1996
Las Vegas, NV
25 April1996
Orange County Cross-Connection Control Group
Anaheim,CA
28 April- 1 May 1996
American Backflow Prevention Association
International Conference
St. Louis, MO
12 June 1996
Western States Symposium Association
Buena Park, CA
ProgramSpec:ialistTrainingCocnse
22-26 July 1996
Los Angeles, CA
FOUNDATION FOR CROSS-CONNECTION CONTROL
AND HYDRAULIC RESEARCH
UNIVERSITY OF SOUTHERN CALIFORNIA
KAP-200 University Park MC-2531
Los Angeles, California 90089·2531
First Class Mail
U. S. Postage Paid
University of
Southern California